US5847626A - Balanced-type surface acoustic wave lattice filter - Google Patents
Balanced-type surface acoustic wave lattice filter Download PDFInfo
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- US5847626A US5847626A US08/655,049 US65504996A US5847626A US 5847626 A US5847626 A US 5847626A US 65504996 A US65504996 A US 65504996A US 5847626 A US5847626 A US 5847626A
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- acoustic wave
- surface acoustic
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- latticed
- wave resonators
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- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
- H03H9/00—Networks comprising electromechanical or electro-acoustic devices; Electromechanical resonators
- H03H9/0023—Balance-unbalance or balance-balance networks
- H03H9/0028—Balance-unbalance or balance-balance networks using surface acoustic wave devices
Definitions
- This invention relates to a balanced-type surface acoustic wave filter used for communication equipment.
- a surface acoustic wave element used for filters has been intensively developed.
- the development of a surface acoustic wave element, and in particular a surface acoustic wave filter is now of great interest.
- several methods have been proposed to form filters used for high frequency bands, especially for several 100 MHz, with the use of surface acoustic wave elements.
- this filter one type comprises a plurality of surface acoustic wave resonators as disclosed in Published Unexamined Japanese Patent Application Nos. (Tokkai Sho) 52-19044 and (Tokkai Hei) 5-183380.
- a so-called multielectrode type filter is disclosed in Published Unexamined Japanese Patent Application No. (Tokkai Sho) 58-154917.
- Another type, which is disclosed in Published Unexamined Japanese Patent Application No. (Tokkai Hei) 3-222512, is characterized by the steps of positioning surface acoustic wave resonators adjacent to each other and connecting these resonators.
- a surface acoustic wave device is disclosed in Published Examined Japanese Utility Model Application No. (Jikko Sho) 58-29627.
- This device uses the above-noted multielectrode type filter as a balanced-type filter and is disposed with a balanced-unbalanced conversion device for input and output. Therefore, as already mentioned above, the number of components is increased, so this filter is not generally used.
- Another example of a balanced-type filter is disclosed in Published Examined Japanese Patent Application No. (Tokkai Hei) 1-208010, in which surface acoustic wave resonators are connected to a lattice type circuit. In this case, however, the resonator is formed as a two-port resonator, and furthermore, this filter has no means to control resonance frequency and antiresonance frequency.
- An object of this invention is to solve the above-mentioned problems in the conventional techniques by providing a balanced-type surface acoustic wave filter which can attain a balanced-type high frequency circuit without connecting a balance-unbalanced conversion circuit.
- a first balanced-type surface acoustic wave filter of this invention comprises a plurality of symmetrical and latticed circuits connected in series, each of the symmetrical and latticed circuits comprises four arms which are connected, where two of the four arms serve as serial arms and the other two arms serve as latticed arms; four surface acoustic wave resonators are disposed, whereby the resonators are respectively arranged in the serial arms and the latticed arms; and a means for adjusting resonant frequencies in the latticed arms and the serial arms to satisfy at least one of the following conditions; (i) an antiresonance frequency in the latticed arms and a resonance frequency in the serial arms are substantially equal to each other, and (ii) a resonance frequency in the latticed arms and an antiresonance frequency in the serial arms are substantially equal to each other.
- a balanced-type surface acoustic wave filter having excellent characteristics can be obtained.
- a balanced-type high frequency circuit can be attained without using a balance-unbalanced conversion circuit, the number of components and costs can be reduced. Furthermore, no intersection of wirings is formed on the substrate surface.
- the balanced-type surface acoustic wave filter further comprises a plurality of connectors for connecting each of four surface acoustic wave resonators, wherein each of the connectors has a substantially same amount of impedance.
- each of the connectors comprises at least one of (i) a connecting electrode formed on the surface of a substrate on which said four surface acoustic wave resonators are formed, and (ii) a wire used for connecting to an external circuit.
- the balanced-type surface acoustic wave filter further comprises a plurality of first connectors for connecting each of the surface acoustic wave resonators located in the latticed arm; and a plurality of second connectors for connecting each of the surface acoustic wave resonators located in the serial arm, wherein an impedance at the first connectors differs from an impedance at the second connectors.
- the ratio of the equivalent parallel capacity between the surface acoustic wave resonator in a serial arm and the surface acoustic wave resonator in a parallel arm is changed from 1-to-1, since at least one of the following conditions is satisfied; (i) an antiresonance frequency in the latticed arms and a resonance frequency in the serial arms are substantially equal to each other, and (ii) a resonance frequency in the latticed arms and an antiresonance frequency in the serial arms are substantially equal to each other, a balanced-type surface acoustic wave filter having excellent characteristics can be obtained.
- each of the first and second connectors comprises at least one of (i) a connecting electrode formed on the surface of a substrate on which the four surface acoustic wave resonators are formed, and (ii) a wire used for connecting to an external circuit.
- a second balanced-type surface acoustic wave filter of this invention comprises a plurality of symmetrical and latticed circuits connected in series, wherein each of the symmetrical and latticed circuits comprises first and second surface acoustic wave resonators, wherein an antiresonance frequency in the first surface acoustic wave resonators and a resonance frequency in the second surface acoustic wave resonators are substantially equal to each other; and an equivalent parallel capacity of the first surface acoustic wave resonators is smaller than an equivalent parallel capacity of the second surface acoustic wave resonators, and the symmetrical and latticed circuits have different ratio in terms of equivalent parallel capacities of the first surface acoustic wave resonators to the second surface acoustic wave resonators.
- the balance-type surface acoustic wave filter of this invention According to the second structure of the balance-type surface acoustic wave filter of this invention, attenuation poles appear in the vicinity of the pass band and away from the pass band. As a result, a balanced-type surface acoustic wave filter suitable to a balanced-type high frequency circuit where the characteristics of damping the frequency bands both in the vicinity of the pass band and away from the pass band are required, can be obtained.
- the third structure of the balanced-type surface acoustic wave filter of this invention ripples in the pass band can be maintained at a low level, and signal reflection, deterioration of characteristics and so on which are generated by difference between the input-output impedance of a balanced-type surface acoustic wave filter and the input-output impedance of a high frequency circuit, can be suppressed.
- input-output impedance of a balanced-type surface acoustic wave filter can be changed appropriately with adoption of a balanced-type circuit, the balanced-type surface acoustic wave filter suitable to a balance-type high frequency circuit can be obtained.
- FIG. 1 is a schematic view of a balanced-type surface acoustic wave filter in a first embodiment of this invention.
- FIG. 3 is a view showing an equivalent circuit of the resonators used for the balanced-type surface acoustic wave filter shown in FIG.1.
- FIG. 4 is a graph showing frequency characteristics of the resonators used for the balanced-type surface acoustic wave filter shown in FIG. 1.
- FIG. 5 is a schematic view showing a circuit for measuring filter characteristics.
- FIG. 6 is a graph showing frequency characteristics of the balanced-type surface acoustic wave filter shown in FIG. 1.
- FIG. 7 is a schematic view of a balanced-type surface acoustic wave filter in a second embodiment of this invention.
- FIG. 8 is a graph showing frequency characteristics of the balanced-type surface acoustic wave filter shown in FIG. 7.
- FIG. 10 is a schematic view of a balanced-type surface acoustic wave filter in a sixth embodiment of this invention.
- FIG. 11 is a graph showing frequency characteristics of the balanced-type surface acoustic wave filter shown in FIG. 10.
- FIG. 12 is a graph showing frequency characteristics of a balanced-type surface acoustic wave filter in a seventh embodiment of this invention.
- FIG. 13 is a view of an equivalent circuit of the balanced-type surface acoustic wave filter in an eighth embodiment of this invention.
- FIG. 14 is a graph showing frequency characteristics of the resonators used for the balanced-type surface acoustic wave filter in an eighth embodiment of this invention.
- FIG. 15 is a graph showing frequency characteristics of one balanced-type surface acoustic wave filter when the ratio of equivalent parallel capacity is approximately 1.
- FIG. 16 is a graph showing frequency characteristics of one balanced-type surface acoustic wave filter when the ratio of equivalent parallel capacity is approximately 0.
- FIG. 17 is a graph showing frequency characteristics of a balanced-type surface acoustic wave filter in an eighth embodiment of this invention.
- FIG. 18 is a view of an equivalent circuit of the balanced-type surface acoustic wave filter in a ninth embodiment of this invention.
- FIG. 24 is a graph showing frequency characteristics of passing loss in the balanced-type surface acoustic wave filter in a tenth embodiment of this invention.
- FIG. 1 is a schematic view of a balanced-type surface acoustic wave filter in a first embodiment of this invention
- FIG. 2 is a view of an equivalent circuit of the balanced-type surface acoustic wave filter shown in FIG. 1.
- a circuit connected in a way shown in FIG. 2 is generally called a symmetrical and latticed circuit.
- FIGS. 1 and 2 A substrate of tantalic acid lithium (LiTaO 3 ) with 36 degrees rotation, Y cut, and X propagation was used, and aluminium was used for the electrodes to form resonators 101s and 102s. Then, as shown in FIGS. 1 and 2, two resonators 101-1 and 101-2 in the serial arm and two resonators 102-1 and 102-2 in the parallel arm are connected in the form of symmetry and lattice to form a balance-type surface acoustic wave filter.
- reference numerals 103 and 104 represent connection parts, or connectors, connecting each resonator, and connecting electrodes formed on the substrate surface are used for the connection parts.
- FIGS. 1 A substrate of tantalic acid lithium (LiTaO 3 ) with 36 degrees rotation, Y cut, and X propagation was used, and aluminium was used for the electrodes to form resonators 101s and 102s. Then, as shown in FIGS. 1 and 2, two resonators 101
- 109-1, 109-2, 109-3 and 109-4 represent inductors which are connected serially to the resonators 101-1, 102-2, 102-1 and 101-2, respectively.
- 105 and 106 represent input terminals, and 107 and 108 represent output terminals. Since connection wires cross on the substrate surface in this embodiment, the input terminal 105 was connected when wire bonding was conducted.
- Semiconductor techniques can be used for crossing on the substrate surface.
- a number of electrode pairs and a number of reflector pairs are determined by the characteristics of a piezoelectric substrate. In this embodiment, the number of both electrode pairs and reflector pairs are actually about 100, but to simplify the description, the number of electrode pairs and reflector pairs are reduced in this figure.
- FIG. 3 shows an equivalent circuit, wherein 201 represents parallel capacity, 202 represents serial capacity, 203 represents a serial inductor, and 204 represents resonance resistance.
- the equivalent parallel capacity refers to the parallel capacity 201 of FIG. 3.
- the ratio of equivalent capacity between the resonator 101 in the serial arm and the resonator 102 in the parallel arm is approximately 1-to-1, so that the antiresonance frequency in the latticed arms (Here, a latticed arm is the same as a parallel arm) and the resonance frequency in the serial arms correspond approximately to each other in substance.
- Frequency characteristics of the resonators 101 and 102 are shown in FIG. 4. As shown in FIG. 4, the resonance frequency of the resonator 102 in the parallel arm is lower than the resonance frequency of the resonator 101 in the serial arm.
- the above-mentioned balanced-type surface acoustic wave filter was converted to an unbalanced-type with the use of a circuit shown in FIG. 5, and the characteristics were measured.
- 501 represents a balun for balanced-unbalanced conversion.
- the reason for converting this balanced-type surface acoustic wave filter to an unbalanced-type is that the measuring equipment used here is for measurement of unbalanced circuits.
- the measurement results are shown in FIG. 6. As shown in FIG. 6, it was confirmed that a balanced-type surface acoustic wave filter constructed in accordance with the present invention has excellent frequency characteristics.
- FIG. 7 is a schematic view of the second embodiment of a balanced-type surface acoustic wave filter of this invention.
- the structure shown in the first embodiment was connected in a two-stage arrangement, which may be used when it is difficult to obtain sufficient out-of-band rejection with a one-stage arrangement.
- the filter when the filter is connected in a two-stage arrangement, there is no part where wirings cross each other on the substrate surface, so that it is considered advantageous that wire bonding can be facilitated.
- a balance-type surface acoustic wave filter having sufficiently high out-of-band rejection could be attained, when compared with the first embodiment with one-stage (cf. FIG. 6).
- the wirings on the substrate surface were designed such that the inductor components connected serially to all the resonators became approximately the same, and a prototype was made.
- the antiresonance frequency in latticed arms and the resonance frequency in serial arms corresponded approximately to each other, so that a balanced-type surface acoustic wave filter having excellent characteristics could be attained.
- the wirings on the substrate surface were designed such that the inductor components connected serially to all the resonators became approximately the same.
- the ratio of equivalent capacity between the resonator 101 in the serial arm and the resonator 102 in the parallel arm was changed, for example, from 1-to-1 to 1-to-2, deterioration of the filter characteristics was also observed, and was probably due to the change of resonance frequency. As expected, this was caused by the inductor components.
- the inductors were the same, since the equivalent parallel capacity of the resonators was almost the same in both the serial arms and in the lattice arms.
- the equivalent capacity is different, it is necessary to change the amount of inductors respectively in the serial arm and in the latticed arm.
- the ratio of equivalent capacity between the resonator 101 in the serial arm and the resonator 102 in the parallel arm was changed to 2-to-1 (that is, the equivalent parallel capacity of the resonator having higher resonance frequency (resonator 101 in the serial arm) was determined to be greater than the equivalent parallel capacity of the resonator having lower resonance frequency (resonator 102 in the parallel arm) (cf. FIG. 4)).
- impedance at connection parts where each resonator in the latticed arms is connected, and the impedance at connection parts to be connected with the serial arms were determined to be different, and in this way, a balanced-type surface acoustic wave filter was designed. The frequency characteristics are shown in FIG. 9.
- the connecting electrode used in the third embodiment was replaced with wires, and wirings on the substrate surface were designed such that inductors entering serially against all the resonators became approximately the same.
- the antiresonance frequency in the latticed arms and the resonance frequency in the serial arms corresponded approximately to each other.
- FIG. 10 is a schematic view showing the sixth embodiment of a balanced-type surface acoustic wave filter of this invention.
- the structure shown in the first embodiment was connected in a three-stage arrangement, which may be used when it is difficult to obtain sufficient out-of-band rejection with either a one-stage or with a two-stage connection.
- the two-stage connection cf. FIG. 7
- FIG. 11 compared with the first embodiment using a one-stage connection (cf. FIG. 6), a balanced-type surface acoustic wave filter having sufficiently high out-of-band rejection could be attained.
- the half-value width became slightly smaller.
- the filter can not be miniaturized.
- the ratio of equivalent capacity in the resonators referred to in the fourth embodiment was changed. More specifically, the ratio of equivalent capacity between the resonator 101 in the serial arm and the resonator 102 in the parallel arm was determined to be 2-to-1. In other words, the equivalent parallel capacity of the resonator having the lower resonance frequency (resonator 102 in parallel arm) was determined to be smaller than the equivalent parallel capacity of the resonator having the higher resonance frequency (resonator 101 in serial arm) (cf. FIG. 4).
- This embodiment creates attenuation poles in the vicinity of pass frequencies of the filter, as shown in FIG. 12, and this is considered especially advantageous when high attenuation is required.
- the antiresonance frequency in the latticed arms and the resonance frequency in the serial arms correspond approximately to each other in substance, but excellent filter characteristics can be also attained when the resonance frequency in the latticed arms and the antiresonance frequency in the serial arms correspond approximately to each other.
- FIG. 13 is a view of an equivalent circuit of the balanced-type surface acoustic wave filter in an eighth embodiment of this invention.
- a substrate of tantalic acid lithium (LiTaO 3 ) with 36 degrees rotation, Y cut, and X propagation was used, and aluminium was used for the electrodes to form resonators 1101s, 1102s, 1103s and 1104s.
- resonators 1101-1101-2 in the serial arm and two resonators 1102-1 and 1102-2 in the parallel arm are connected in the form of symmetry and lattice to form a first surface acoustic wave filter.
- two resonators 1103-1' and 1103-2' in the serial arm and two resonators 1104-1' and 1104-2' in the parallel arm are connected in the form of symmetry and lattice to form a second surface acoustic wave filter.
- the first and second surface acoustic wave filters are connected in series.
- reference numerals 1105 and 1106 represent input terminals
- 1107 and 1108 represent output terminals.
- 1109s represent inductors which are connected serially to all the resonators.
- the antiresonance frequency of the two resonators 1101s in the serial arms and the resonance frequency of the two resonators 1102s in the parallel arms correspond approximately to each other in substance.
- the antiresonance frequency of the two resonators 1103s in the serial arms and the resonance frequency of the two resonators 1104s in the parallel arms correspond approximately to each other in substance.
- Frequency characteristics in impedance of the resonators 1101s and 1102s are shown in FIG. 14.
- the antiresonance frequency of the resonator 1101 in the serial arm and the resonance frequency of the resonator 1102 in the parallel arm correspond approximately to each other in substance. That is, the resonance frequency of the resonator 1101 in the serial arm is set to be lower than the resonance frequency of the resonator 1102 in the parallel arm.
- a symmetrical and latticed circuit is a so-called Wheatstone bridge, where the output of the circuit becomes zero level at the frequency at which the square of the impedance of the resonator 1101 in the serial arm and the square of the impedance of the resonator 1102 in the parallel arm become the same, namely, the impedance of the resonator 1101 in the serial arm and the impedance of the resonator 1102 in the parallel arm become the same.
- Attenuation poles appear in transmission characteristics of the filter only when the equivalent parallel capacity of the resonator 1101 in the serial arm is smaller than the equivalent parallel capacity of the resonator 1102 in the parallel arm. The reason is as follows.
- Attenuation poles appear in transmission characteristics of the filter namely, the impedance of the resonator 1101 in the serial arm and the impedance of the resonator 1102 in the parallel arm become the same on condition that an inequality Imag(Z 1101 ) ⁇ Imag(Z 1102 ) is satisfied, except the vicinity of the resonance frequencies and the antiresonance frequencies, when the impedance of the resonator 1101 in the serial arm is Imag(Z 1101 ), the impedance of the resonator 1102 in the parallel arm is Imag(Z 1102 ).
- the impedances Imag(Z 1101 ) and Imag(Z 1102 ) of the resonators 1101, 1102 increase monotonically to the resonance frequency, and the resonance frequency of the resonator 1101 in the serial arm is set to be lower than the resonance frequency of the resonator 1102 in the parallel arm, if the inequality Imag(Z 1101 ) ⁇ Imag(Z 1102 ) is satisfied, Imag(Z 1101 ) and Imag(Z 1102 ) become identical at a certain frequency for certain.
- the frequency characteristics of passing loss in the balanced-type surface acoustic wave filter is improved by controling input-output impedance of the symmetrical and latticed balanced-type surface acoustic wave filter.
- FIG. 18 is a view of an equivalent circuit of the balanced-type surface acoustic wave filter in a ninth embodiment of this invention.
- a substrate of tantalic acid lithium (LiTaO 3 ) with 36 degrees rotation, Y cut, and X propagation was used, and aluminium was used for the electrodes to form resonators 1201, 1202.
- resonators 1201, 1202. As shown in FIG. 18, two resonators 1201-1 and 1201-2 in the serial arm and two resonators 1202-1 and 1202-2 in the parallel arm are connected in the form of symmetry and lattice to form a balanced-type surface acoustic wave filter.
- FIG. 18 is a view of an equivalent circuit of the balanced-type surface acoustic wave filter in a ninth embodiment of this invention.
- reference numerals 1203 and 1204 represent input terminals, and 1205 and 1206 represent output terminals.
- 1207s represent inductors which are connected serially to all the resonators.
- the antiresonance frequency of the two resonators 1201-1 and 1201-2 in the serial arms and the resonance frequency of the two resonators 1202-1 and 1202-2 in the parallel arms correspond approximately to each other in substance.
- the equivalent parallel capacity of the resonator 1201 in the serial arm is set to be lower than the equivalent parallel capacity of the resonator 1202 in the parallel arm.
- the input-output impedance of the balanced-type surface acoustic wave filter is Z
- the passing center frequency of the balance-type surface acoustic wave filter is F
- a correction factor is K
- a balanced-type surface acoustic wave filter having the pass band of 900 MHz is used. As shown in FIGS.
- ripples in the pass band when a correction factor K is smaller than 0.6, ripples in the pass band become conspicuous, and a large ripple appears at a frequency lower than the pass band.
- ripples in the pass band when a correction factor is larger than 1.8, ripples in the pass band become conspicuous, and a large ripple appears at a frequency higher than the pass band. Accordingly, ripples in the pass band can be maintained at a low level with a correction factor of 0.6 ⁇ K ⁇ 1.8.
- the frequency characteristics of passing loss in the balanced-type surface acoustic wave filter can be improved by introducing the correction factor K, and controlling input-output impedance of the balanced-type surface acoustic wave filter. For example, even when the balanced-type surface acoustic wave filter having input-output impedance of 40 ⁇ is connected to high frequency circuit having input-output impedance 50 ⁇ , the required characteristics can be satisfied.
- the correction factor K is in appropriate range.
- a correction factor K is larger than 0.6, and smaller than 1.8 as mentioned above, signal reflection, deterioration of characteristics, etc., which are generated by the difference between the input-output impedance of a balanced-type surface acoustic wave filter and the input-output impedance of a high frequency circuit, can be suppressed. As a result, the balanced-type surface acoustic wave filter having excellent characteristics can be obtained.
- ripples in the pass band can be maintained at a low level, and signal reflection, deterioration of characteristics, etc. can be suppressed.
- input-output impedance of a balanced-type surface acoustic wave filter can be changed appropriately with adoption of a balance-type circuit, the balanced-type surface acoustic wave filter suitable to a balanced-type high frequency circuit can be obtained.
- the frequency characteristics of passing loss in the above-mentioned balanced-type surface acoustic wave filter is shown in FIG. 24.
- a balanced-type surface acoustic wave filter having a high attenuation over wide-ranging frequencies can be obtained.
- a substrate having substantially the same piezoelectric properties for example, a quartz crystal substrate or a substrate of lithium niobate (LiNbO 3 ) may be used as well.
- a piezoelectric substance by using a piezoelectric substance, a balanced-type surface acoustic wave filter having substantially the same excellent characteristics can be attained.
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Abstract
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Claims (7)
Priority Applications (1)
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US08/655,049 US5847626A (en) | 1994-02-22 | 1996-05-29 | Balanced-type surface acoustic wave lattice filter |
Applications Claiming Priority (6)
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JP6-024027 | 1994-02-22 | ||
JP2402794 | 1994-02-22 | ||
US38646095A | 1995-02-10 | 1995-02-10 | |
JP8-100012 | 1996-04-22 | ||
JP10001296A JPH09289434A (en) | 1996-04-22 | 1996-04-22 | Balanced surface acoustic wave filter |
US08/655,049 US5847626A (en) | 1994-02-22 | 1996-05-29 | Balanced-type surface acoustic wave lattice filter |
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US38646095A Continuation-In-Part | 1994-02-22 | 1995-02-10 |
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US08/655,049 Expired - Lifetime US5847626A (en) | 1994-02-22 | 1996-05-29 | Balanced-type surface acoustic wave lattice filter |
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Cited By (17)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20010043024A1 (en) * | 2000-06-27 | 2001-11-22 | Murata Manufacturing Co., Ltd . | Surface acoustic wave device |
US6344705B1 (en) * | 1998-02-06 | 2002-02-05 | Thomson-Csf | Filter with surface acoustic wave resonators |
GB2365236A (en) * | 2000-02-07 | 2002-02-13 | Murata Manufacturing Co | Balanced surface acoustic wave ladder filter |
US6377140B1 (en) * | 1999-07-09 | 2002-04-23 | Oki Electric Industry Co., Ltd. | Saw resonator filter with bridged-T configuration |
EP1204205A2 (en) * | 2000-11-06 | 2002-05-08 | Alps Electric Co., Ltd. | Lattice filter with ripple in passing band eliminated and with passing band widened |
WO2002082647A1 (en) * | 2001-03-23 | 2002-10-17 | Infineon Technologies Ag | Filter device |
US6549100B2 (en) * | 2000-02-07 | 2003-04-15 | Murata Manufacturing Co., Ltd. | Surface acoustic wave lattice filter with different lattice and series arm capacitance ratios and communication device using same |
US6713940B2 (en) * | 2001-01-10 | 2004-03-30 | Murata Manufacturing Co., Ltd. | Surface acoustic wave device |
US20040196119A1 (en) * | 2003-02-24 | 2004-10-07 | Teruhisa Shibahara | Surface acoustic wave filter and communication apparatus |
US20080117001A1 (en) * | 2006-11-22 | 2008-05-22 | Fujitsu Media Devices Limited | Filter Device |
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US20090273408A1 (en) * | 2008-04-30 | 2009-11-05 | Fujitsu Limited | Filter duplexer and communication device |
US20100188166A1 (en) * | 2009-01-27 | 2010-07-29 | Fujitsu Limited | Filter, duplexer and communication module |
US20120256705A1 (en) * | 2011-04-07 | 2012-10-11 | Commissariat A L'energie Atomique Et Aux Energies Alternatives | Device using a filter with resonators |
CN104601141A (en) * | 2009-05-14 | 2015-05-06 | 天工松下滤波方案日本有限公司 | Antenna sharing device |
US20210257993A1 (en) * | 2016-03-11 | 2021-08-19 | Akoustis, Inc. | Acoustic wave resonator rf filter circuit device |
US11274046B2 (en) | 2016-05-31 | 2022-03-15 | Skyworks Solutions, Inc. | High Q modified barium tantalate for high frequency applications |
Citations (11)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2696591A (en) * | 1950-12-28 | 1954-12-07 | Cie Ind Des Telephones | Lattice-type reactive quadripoles |
JPS5219044A (en) * | 1975-08-04 | 1977-01-14 | Nippon Telegr & Teleph Corp <Ntt> | Surface acoustic wave filter |
JPS5829627A (en) * | 1981-08-13 | 1983-02-21 | Shigeo Takamura | Drilling method of contact lens |
JPS58154917A (en) * | 1982-03-10 | 1983-09-14 | Hitachi Ltd | Band pass filter of surface acoustic wave |
US4785270A (en) * | 1987-12-30 | 1988-11-15 | Motorola Inc. | Monolithic lattice saw filter |
JPH02127810A (en) * | 1988-11-07 | 1990-05-16 | Nec Corp | Surface acoustic wave filter |
US5028893A (en) * | 1990-03-21 | 1991-07-02 | Delco Electronics Corporation | Switched capacitor filters with continuous time control |
JPH03222512A (en) * | 1990-01-29 | 1991-10-01 | Oki Electric Ind Co Ltd | Polarized type saw resonator filter |
US5093638A (en) * | 1990-11-05 | 1992-03-03 | Motorola, Inc. | Unbalanced saw filter |
EP0541284A1 (en) * | 1991-10-28 | 1993-05-12 | Fujitsu Limited | Surface acoustic wave filter |
US5508667A (en) * | 1993-08-04 | 1996-04-16 | Advanced Saw Products Sa | Balanced bridge saw filter |
-
1996
- 1996-05-29 US US08/655,049 patent/US5847626A/en not_active Expired - Lifetime
Patent Citations (11)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2696591A (en) * | 1950-12-28 | 1954-12-07 | Cie Ind Des Telephones | Lattice-type reactive quadripoles |
JPS5219044A (en) * | 1975-08-04 | 1977-01-14 | Nippon Telegr & Teleph Corp <Ntt> | Surface acoustic wave filter |
JPS5829627A (en) * | 1981-08-13 | 1983-02-21 | Shigeo Takamura | Drilling method of contact lens |
JPS58154917A (en) * | 1982-03-10 | 1983-09-14 | Hitachi Ltd | Band pass filter of surface acoustic wave |
US4785270A (en) * | 1987-12-30 | 1988-11-15 | Motorola Inc. | Monolithic lattice saw filter |
JPH02127810A (en) * | 1988-11-07 | 1990-05-16 | Nec Corp | Surface acoustic wave filter |
JPH03222512A (en) * | 1990-01-29 | 1991-10-01 | Oki Electric Ind Co Ltd | Polarized type saw resonator filter |
US5028893A (en) * | 1990-03-21 | 1991-07-02 | Delco Electronics Corporation | Switched capacitor filters with continuous time control |
US5093638A (en) * | 1990-11-05 | 1992-03-03 | Motorola, Inc. | Unbalanced saw filter |
EP0541284A1 (en) * | 1991-10-28 | 1993-05-12 | Fujitsu Limited | Surface acoustic wave filter |
US5508667A (en) * | 1993-08-04 | 1996-04-16 | Advanced Saw Products Sa | Balanced bridge saw filter |
Non-Patent Citations (1)
Title |
---|
1974 Ultrasonics Symposium Proceedings; New York, US: S.C. Tseng et al: SAW Planar Network. * |
Cited By (36)
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US6344705B1 (en) * | 1998-02-06 | 2002-02-05 | Thomson-Csf | Filter with surface acoustic wave resonators |
US6377140B1 (en) * | 1999-07-09 | 2002-04-23 | Oki Electric Industry Co., Ltd. | Saw resonator filter with bridged-T configuration |
US6535080B2 (en) | 2000-02-07 | 2003-03-18 | Murata Manufacturing Co., Ltd. | Surface acoustic wave ladder filter with balanced input and output terminals |
GB2365236A (en) * | 2000-02-07 | 2002-02-13 | Murata Manufacturing Co | Balanced surface acoustic wave ladder filter |
US6549100B2 (en) * | 2000-02-07 | 2003-04-15 | Murata Manufacturing Co., Ltd. | Surface acoustic wave lattice filter with different lattice and series arm capacitance ratios and communication device using same |
GB2365236B (en) * | 2000-02-07 | 2002-10-02 | Murata Manufacturing Co | Surface acoustic wave filter |
US20040124740A1 (en) * | 2000-06-27 | 2004-07-01 | Murata Manufacturing Co., Ltd. | Surface acoustic wave device |
US20010043024A1 (en) * | 2000-06-27 | 2001-11-22 | Murata Manufacturing Co., Ltd . | Surface acoustic wave device |
US6882249B2 (en) * | 2000-06-27 | 2005-04-19 | Murata Manufacturing Co., Ltd. | Surface acoustic wave device |
EP1204205A2 (en) * | 2000-11-06 | 2002-05-08 | Alps Electric Co., Ltd. | Lattice filter with ripple in passing band eliminated and with passing band widened |
US6624725B2 (en) * | 2000-11-06 | 2003-09-23 | Alps Electric Co., Ltd. | Lattice filter with ripple in passing band eliminated and with passing band widened |
EP1204205A3 (en) * | 2000-11-06 | 2004-01-07 | Alps Electric Co., Ltd. | Lattice filter with ripple in passing band eliminated and with passing band widened |
US6713940B2 (en) * | 2001-01-10 | 2004-03-30 | Murata Manufacturing Co., Ltd. | Surface acoustic wave device |
WO2002082647A1 (en) * | 2001-03-23 | 2002-10-17 | Infineon Technologies Ag | Filter device |
US20040196119A1 (en) * | 2003-02-24 | 2004-10-07 | Teruhisa Shibahara | Surface acoustic wave filter and communication apparatus |
EP1453198A3 (en) * | 2003-02-24 | 2006-03-01 | Murata Manufacturing Co., Ltd. | Surface acoustic wave filter and communication apparatus |
US7295089B2 (en) | 2003-02-24 | 2007-11-13 | Murata Manufacturing Co., Ltd. | Surface acoustic wave filter and communication apparatus |
US20080117000A1 (en) * | 2006-11-22 | 2008-05-22 | Fujitsu Media Devices Limited | Filter device |
US7864002B2 (en) * | 2006-11-22 | 2011-01-04 | Taiyo Yuden Co., Ltd | Filter device with balanced signal input and output terminals |
US7880566B2 (en) * | 2006-11-22 | 2011-02-01 | Taiyo Yuden Co., Ltd. | Balanced lattice filter device |
US20080117001A1 (en) * | 2006-11-22 | 2008-05-22 | Fujitsu Media Devices Limited | Filter Device |
US20090273408A1 (en) * | 2008-04-30 | 2009-11-05 | Fujitsu Limited | Filter duplexer and communication device |
US8093960B2 (en) * | 2008-04-30 | 2012-01-10 | Taiyo Yuden Co., Ltd. | Filter duplexer and communication device |
US9397634B2 (en) | 2009-01-27 | 2016-07-19 | Taiyo Yuden Co., Ltd. | Filter, duplexer and communication module |
US20100188166A1 (en) * | 2009-01-27 | 2010-07-29 | Fujitsu Limited | Filter, duplexer and communication module |
US8648670B2 (en) | 2009-01-27 | 2014-02-11 | Taiyo Yuden Co., Ltd. | Filter, duplexer and communication module |
CN104601141B (en) * | 2009-05-14 | 2017-10-03 | 天工滤波方案日本有限公司 | Notch diplexer |
CN104601141A (en) * | 2009-05-14 | 2015-05-06 | 天工松下滤波方案日本有限公司 | Antenna sharing device |
US8907747B2 (en) * | 2011-04-07 | 2014-12-09 | Commissariat A L'energie Atomique Et Aux Energies Alternatives | Device using a filter with resonators |
US20120256705A1 (en) * | 2011-04-07 | 2012-10-11 | Commissariat A L'energie Atomique Et Aux Energies Alternatives | Device using a filter with resonators |
US20210257993A1 (en) * | 2016-03-11 | 2021-08-19 | Akoustis, Inc. | Acoustic wave resonator rf filter circuit device |
US11274046B2 (en) | 2016-05-31 | 2022-03-15 | Skyworks Solutions, Inc. | High Q modified barium tantalate for high frequency applications |
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